Electrical control unit

ABSTRACT

A device, preferably of the plug-in type, which is connected in an electrical master circuit and operates when the master circuit is energized to momentarily open and/or close a contact in an independent slave circuit and thereby perform a control function. The operation is momentary even though the master circuit is maintained in the energized condition.

United n 1 Hudimac, Jr.

May 15, 1973 ELECTRICAL-CONTROL UNIT George S. Hudimac, Jr., Allentown, Pa.

Assignee: Mechanical Service Co., Inc., Allentown, Pa.

June 12, 1972 Inventor:

Filed:

Appl. No.: 261,706

US. Cl. ..307/108, 317/113, 317/151 Int. Cl. ..H03k 3/00 Field of Search ..307/l50, 106, 108;

[56] References Cited UNITED STATES PATENTS 2,764,715 9/1956 Lorenz ..317/15l 2,999,222 9/1961 Adams ..3l7/1l3 X Primary ExaminerRobert K. Schaefer Assistant Examiner-M. Ginsburg Att0rney- Frederick J. ()lsson [57] ABSTRACT 4 Claims, 3 Drawing Figures I20 VOlTS 60 CYCL FS .PATENIEDMAY 15 I975 SHEET 3' [IF 3 ELECTRICAL CONTROL UNIT This invention relates to electrical circuit devices and in particular relates to control devices for such circuits.

More specifically, the invention relates to a device which is incorporated in an electrical master circuit and functions, when the circuit is energized, to momentarily open and/or close switches in controlled or slave circuits so that the operating condition of the slave circuit is momentarily changed and also that this is effected even though the master circuit is maintained in the energized condition over an extended period of time.

The invention contemplates a full wave rectifier, the input of which is connected to an a.c. master circuit and the output of which is shunted by two parallel circuits, one being a resistor and the other being a seriesconnected-relay coil and capacitor. These elements are arranged so that when an operating switch in the master circuit is actuated a dc. voltage appears across the capacitor and relay coil where the coil is energized while the capacitor is being charged. Energizing of the coil operates its contacts. When the capacitor is fully charged the relay is no longer active so that its contacts revert to their normal state. The relay and capacitor remain in this condition until the master switch is opened whereupon the capacitor discharges thru the resistor and the combination is automatically reset.

There are certain fundamental advantages of the invention and the more important of which are mentioned following:

a. the device can be constructed as a small plug-in unit or in a larger form as a non-plug-in unit;

b. as a plug-in type the components can be mounted so that the same are enclosed within a small housing and supported on a standard socket;

c. the standard socket uses the standard pin numbers which makes the device ideally compatible with conventional power circuitry;

d. the number of controlled or slave circuits is limited only by the number of contacts on the relay and the number of pins in the socket available for use;

e. the device can replace a standard socket mounted relay which controls an external off-on circuit.

The details of the invention and other advantages thereof will be apparent from the following description taken in connection with the following drawings wherein:

FIG. 1 is a circuit diagram illustrating the invention as used in connection with a master circuit having an initiating switch which is normally open;

FIG. 2 is a circuit diagram illustrating the invention as used in connection with a master circuit having an initiating switch which is normally closed; and

FIG. 3 is an exploded perspective view of a preferred form of plug-in unit incorporating the invention.

In FIG. 1, the circuit is shown with relation to standard eight-pin octal base, the base being indicated by the dotted lines 11. The pins of the base are represented by the numerals 1 thru 8, each enclosed within a small circle. The standard numbering system is used on the pins. It will be understood that the circuits shown outside of the circular line 11 are external to the base and the connection to the pins being thru a terminal board as mentioned below.

In accordance with practice, the pins 2 and 7 are the power input pins. The leads are connected to a master circuit. The normallyopen initiating switch 14 is incorporated in the lead 12. Normally the master circuit is rated at 120 volts, a.c., single phase, 600. The switch 14 will normally be opened when the master circuit is energized but which can be closed as desired. The switch 14 may be manually or automatically operated.

The full wave rectifier 15 has a.c. input terminals 16 and 17 which are respectively connected to the power input pins 2 and 7. For the type of master circuit mentioned the rectifier is rated 5 amps, 400 volts a.c. A transient voltage suppresson 20 is connected across the terminals 16 and 17 to protect the rectifier. Normally the suppressor will comprise a pair of back to back diodes and is rated at 3 amps, 208 volts a.c. The suppressor will short circuit the rectifier at about 208 volts peak.

The rectifier has d.c. output terminals 21 and 22. A resistor 23 is connected across the dc. output terminals. The resistor is rated at l0 watts, l0,000 ohms. A capacitor 24 is connected in series with relay coil 25 and the pair are connected in parallel with the resistor 23 across the dc. output terminals 21 and 22. The capacitor is rated at 4 mfd., 450 volts d.c. The rating of the relay coil is volts do.

The relay includes contacts 25a, 25b, 25c, 25d which are actuated by the energizing of the relay coil 25. The relay has a spring loaded armature carrying the movable parts of the contacts. The spring biases the armature to move the contacts in one direction to a normal position and the coil moves the armature in the opposite direction against the force of the spring.

The contacts 25a are normally closed by the spring action and are connected between pins 4 and 1. A slave connected to the pins 4 and 1 would be de-energized when the contacts 25a are open of the relay coil. The contacts 25b are normally open by virtue of the spring action and are connected between the pins 3 and 1, aslave circuit connected to the pins will be energized when the contacts are closed by the relay coil.

The contacts 25c and 25d are connected between the pins 5, 6 and 8 and function to control a slave circuit in the same manner as the contacts 25a and 25b.

The manner with which the foregoing circuit operates so that there is a momentary opening or closing of the slave circuit will next be described.

With the closure of the external switch 14, a.c. is supplied to the terminals 16 and 17 and the a.c. is rectified and appears as do. on the output terminals 21 and 22. This causes the capacitor 24 to charge. As the capacitor charges, the relay coil 25 is energized and the con-' tacts 25a thru 25d are actuated. When the capacitor is fully charged there is no further current flow in the coil 25 so it loses its holding power and the contacts 25a through 25d are spring returned to their normal position. The circuit will remain in the foregoing condition until the external switch 14 is opened.

With the opening of the switch 14, the do. is removed from the rectifier output terminals 21 and 22. Thus the capacitor discharges thru the relay coil 25 and resistor 23. Due to the size of the resistor, the current flowing thru the relay coil will not cause false actuation of the relay. In other words, the coil does not pick up the contacts 250 thru 25d.

A typical example of such a master circuit is a die control circuit where initiating push button switches must be closed and then quickly released or opened by the operator in order for the die mechanism to properly function. The circuit of FIG. 1 can be used in the control system of a die and avoid dependence on the operator to release the switch. The invention will set the die into motion even if the operator holds in the switch. In such a circuit the leads 12 and 13 are connected into the control circuit with the switch 14 being the initiating switch and one of the normally open switches 25b or 25d is series-connected with the die-closing solenoid.

The arrangement of FIG. 2 is for those cases where the external master circuit has an initiating switch normally closed when the master circuit is energized and which is momentarily opened and/or closed as desired. In this design a greater number of pins are required and the octal base 30 is in the standard 11 pin form. The pins have the standard number system as indicated by the numerals 1 through 11 within small circles.

The power pins 2 and are respectively connected to the leads 31 and 32. The lead 31 is connected to one side of the master circuit and the lead 32 is connected to the other side of the circuit thru the single poledouble throw switch 33. The switch has pole 33a and contacts 33b and 330.

The rectifier 34, the voltage suppressor 35, the resistor 36, the capacitor 40 and relay coil 41 have the same construction and rating as the corresponding parts in FIG. 1 and function in the same manner.

The a.c. input terminal 42 of the rectifier is connected to the power input pin 2 and the a.c. input 43 is connected via the contacts 44a of the power input relay coil 44 to the power pin 10. The contacts 44a assure that when the pole 33a is positioned on the contact 33b there is no power transfer to the rectifier.

One side of the coil 44 is connected to the a.c. input terminal 42 and the other side is connected via pin 8 to the terminal 330 and also thru contact 44b and pin 9 to the pole 33a.

Assume the master circuit of FIG. 2 is energized and that the pole 33a of the switch is contact 33b. There is no power input to the rectifier 34. The switch 33 is mechanically connected so that the pole 33a, at some desired time, momentarily engages the contact 336 and then moves back to the contact 33b. At the instant the pole engages the contact 330 the relay coil 44 is energized and this causes contacts 44b to hold up the relay. The contacts 44a also close. When the pole 33a then returns to the contacts 33b, a.c. power is supplied to the rectifier 34. The effect of this is to momentarily actuate switches 41a 41d which respectively function to momentarily open and/or close connected slave circuits in the same manner as explained in connection with FIG. 1.

In FIG. 3 I have shown the preferred structure for incorporating the invention in a plug-in type arrangement and utilizing the circuit of FIG. 1.

The conventional terminal board 50 has a central section 51 provided with a plurality of apertures 52 within which are pin receptacles not shown. The apertures and receptacles are arranged in a circular fashion so as to receive the pins on a standard 18 pin octal base. The board has a plurality of terminals 53 which are respectively independently connected to the pin receptacles.

A flat rectangular support base 54 includes the standard 18 pin octal base on the bottom side, the pins of which are shown at 55. On the top side of the base is fixed an upwardly extending column 56.

Centrally mounted on the column is a standard relay assembly, the coil of the relay is indicated at 57, the armature at 60, the contact block at 61 and the contacts at 62. The block is spaced upwardly from the base.

On the top of the column above the relay assembly is fixed a full wave rectifier assembly 63. The capacitor and voltage suppressor are disposed above the rectifier and the position of the same is indicated by the dotted lines 64 and 65. On the left hand side, closely adjacent the relay assembly and extending vertically between the base and rectifier is the resistor indicated by the dotted lines 66.

For the sake of clarity I have not shown the various wire connections between the relay, rectifier, capacitor, resistor and voltage suppressor.

The nested arrangement of the above described components provides for the same to be enclosed within a hollow housing 67 which fits down on top of the base and is held in a position by screws 68 extending upwardly thru the base.

I claim:

1. In a plug-in power unit to cause momentary operation of a controlled circuit:

a terminal board including a plurality of pin receptacles and a plurality of terminals respectively connected to the pin receptacles;

a flat base having a plurality of pins extending from one side thereof and arranged to respectively fit into the pin receptacles on the terminal board;

a column connected to and extending upwardly from the opposite side of said base;

a relay assembly including contacts supported by said column and spaced above said base;

a rectifier connected to the top of said column and overlying said relay assembly;

a capacitor, a resistor and a voltage suppressor, the capacitor and suppressor being disposed on top of said rectifier and the resistor extending upwardly adjacent said column; and

a hollow housing mounted on said base and enclosing said column, relay assembly, rectifier capacitor, resistor and voltage suppressor.

2. In a power unit to cause momentary operation of a controlled circuit:

power input terminals for connecting to a source of a.c. voltage, the source having a normally open switch for electrically connecting and disconnecting the source with the input terminals;

a full wave rectifier having a.c. input terminals and d.c. output terminals, the a.c. input terminals being connected between said power input terminals;

an a.c. voltage suppressor connected across said power input terminals;

a resistor connected across said d.c. output terminals;

a d.c. relay having coil and spring biased contact means moveable between a normal position and an operating position, the contact means being moved to said normal position by the spring when the coil is de-energized and being moved to the operating position by the energizing of the coil;

a capacitor connected in series with said coil, the coil and the capacitor being connected across said d.c. output terminals; and the rectifier, resistor and capacitor being constructed and arranged so that when the source switch is closed the rectifier imposes a d.c. voltage across the capacitor and relay coil so that the coil is energized during the time the capacitor is being charged, the energizing causing the relay contact means to move against the force of the spring and when the capacitor is fully charged the energizing of the coil terminating whereby the spring returns the contact means to said normal position with the capacitor remaining charged and the relay contact means remaining in said normal position until the source switch is opened, the opening of the source switch causing the capacitor to discharge thru the resistor, the discharge being in a direction so that the coil does not move the contact means.

3. A construction in accordance with claim 2 wherein said contact means includes a set of normally open contacts and a set of normally closed contacts electrically connected to each other and to terminals so that a load can be connected across the normally open contacts or alternatively across the normally closed contacts.

4. A power unit to cause momentary operation of a controlled circuit:

first and second power input terminals for connection to a source of a.c. voltage;

a full wave rectifier having first and second a.c. input terminals and dc. output terminals;

an electrical connection between the first a.c. input terminal and the first power input terminal;

an electrical connection between the second a.c.

input terminal and the second power input terminal, the connection including normally-open power input relay contacts;

a single pole, double throw switch, the pole being connected to one side of said source of a.c. voltage and one contact being connected to said second a.c. input terminal;

an a.c. voltage suppressor connected across said power input terminals;

a resistor connected across said d.c. output terminals;

a dc relay having coil and contact means to be actuated by the energizing and de-energizing of the coil;

a capacitor connected in series with said coil, the coil and capacitor being connected across said d.c. output terminals; and

an a.c. input relay having coil and contact means, one side of the coil being connected to said first power input terminal and the other side of the coil being connected to the other contact of the said switch, one of the contact means of the a.c. input relay being said normally open power input contacts and another of the contact means of the a.c. input relay being normally open contacts connected between said other side of the coil and the pole of said switch. 

1. In a plug-in power unit to cause momentary operation of a controlled circuit: a terminal board including a plurality of pin receptacles and a plurality of terminals respectively connected to the pin receptacles; a flat base having a plurality of pins extending from one side thereof and arranged to respectively fit into the pin receptacles on the terminal board; a column connected to and extending upwardly from the opposite side of said base; a relay assembly including contacts supported by said column and spaced above said base; a rectifier connected to the top of said column and overlying said relay assembly; a capacitor, a resistor and a voltage suppressor, the capacitor and suppressor being disposed on top of said rectifier and the resistor extending upwardly adjacent said column; and a hollow housing mounted on said base and enclosing said column, relay assembly, rectifier capacitor, resistor and voltage suppressor.
 2. In a power unit to cause momentary operation of a controlled circuit: power input terminals for connecting to a source of a.c. voltage, the source having a normally open switch for electrically connecting and dis-connecting the source with the input terminals; a full wave rectifier having a.c. input terminals and d.c. output terminals, the a.c. input terminals being connected between said power input terminals; an a.c. voltage suppressor connected across said power input terminals; a resistor connected across said d.c. output terminals; a d.c. relay having coil and spring biased contact means moveable between a normal position and an operating position, the contact means being moved to said normal position by the spring when the coil is de-energized and being moved to the operating position by the energizing of the coil; a capacitor connected in series with said coil, the coil and the capacitor being connected across said d.c. output terminals; and the rectifier, resistor and capacitor being constructed and arranged so that when the source switch is closed the rectifier imposes a d.c. voltage across the capacitor and relay coil so that the coil is energized during the time the capacitor is being charged, the energizing causing the relay contact means to move against the force of the spring and when the capacitor is fully charged the energizing of the coil terminating whereby the spring returns the contact means to said normal position with the capacitor remaining charged and the relay contact means remaining in said normal position until the source switch is opened, the opening of the source switch causing the capacitor to discharge thru the resistor, the discharge being in a direction so that the coil does not move the contact means.
 3. A construction in accordance with claim 2 wherein said contact means includes a set of normally open contacts and a set of normally closed contacts electrically connected to each other and to terminals so that a load can be connected across the normally open contacts or alternatively across the normally closed contacts.
 4. A power unit to cause momentary operation of a controlled circuit: first and second power input terminals for connection to a source of a.c. voltage; a full wave rectifier having first and second a.c. input terminals and d.c. output terminals; an electrical connection between the first a.c. input terminal and the first power input terminal; an electrical connection between the second a.c. input terminal and the second power input terminal, the connEction including normally-open power input relay contacts; a single pole, double throw switch, the pole being connected to one side of said source of a.c. voltage and one contact being connected to said second a.c. input terminal; an a.c. voltage suppressor connected across said power input terminals; a resistor connected across said d.c. output terminals; a d.c. relay having coil and contact means to be actuated by the energizing and de-energizing of the coil; a capacitor connected in series with said coil, the coil and capacitor being connected across said d.c. output terminals; and an a.c. input relay having coil and contact means, one side of the coil being connected to said first power input terminal and the other side of the coil being connected to the other contact of the said switch, one of the contact means of the a.c. input relay being said normally open power input contacts and another of the contact means of the a.c. input relay being normally open contacts connected between said other side of the coil and the pole of said switch. 